Electrical motors are used in a variety of applications. These applications include refrigeration units, pumping systems, and the like. Typically, the input power to a power supply for operating an electrical motor or other electrical equipment can vary depending upon the environment in which the power supply will be used. For example, in some environments, single phase, 50 or 60 Hz AC power is available to power an electrical motor, while in other environments, the input power is three phase, 50 or 60 Hz AC power. Not only does the number of phases differ for different sources of input AC power, but the voltage levels differ as well. Single phase input power can include voltages in a range of 100 VAC to 277 VAC and three phase input power can include voltages in a range of 208 VAC to 575 VAC.
Connecting AC electrical power directly to an electrical motor is rarely the most efficient manner of operating an electrical motor or other electrical equipment. The attenuation of noise in the input power, regulation of the voltage and current levels with reference to the changing loads, and controlling the power factor for these loads are important considerations. Additionally, some electrical equipment requires conversion of the AC power to DC power before the power can be effectively applied to the equipment. The regulation, AC/DC conversion, and power factor control circuits vary for single phase and multi-phase input power sources as well as for different voltage levels. Being able to provide a single electrical circuit for regulating and controlling different sources of AC power for electrical power supplies would be useful.